Photolithographic processes often involve deposition of anti-reflection coatings (ARCs) to reduce reflection of light from other layers disposed underneath the photoresist. For example, the ARC layer may prevent a standing wave effect caused by interference between incident light toward the photoresist layer and reflected light from the layer to be etched. Various organic and inorganic ARC layers have been developed in efforts to reduce the size of features and to increase their density. Silicon-containing anti-reflection coatings (SiARCs) are promising candidates for various applications, such as applications involving hard masks, because the silicon content of such coatings can be specifically tuned to provide various optical properties. However, removal of SiARCs, especially SiARCs with high silicon content, is difficult, and new processing methods for removing these materials and other layers are needed in semiconductor processing.